Heat treating equipment



Mmh28,1939.; H .;.FLE1- HER HAL 2,152,138

. HEAT-YTREATING E UIPME T Filed April 20, 1937 s Sheets-Sheet 1' James Fletcher g Earl E. S'c/Toessovy ATTORNEY.

' March 28, 1939. v .1. FLETCHER ET AL I 2,152,133 V HEAT TREATING EQUIPMENT Filed April 20, 1957 I 5 Shets-Sheet 2 17: 42 V V 5 3 V y 50 /46 V I 1 V 7 8 22 4 1 Y 20 "5 56 I 36 1 INVENTQRS James F/ezicher Earl 'E. choessow a 33 ATTOR EY.

March 28, 1939. Q J. FLETCHER ET AL 2 HEAT TREATING EQUIPMENT Filed April 20, 1937 5 She ets-Sheet 5 INVENTORS E James F/e taker Earl 56/1065501 1 'ATTORNEY.

March-28, 1939- J J. FLETCHER ET AL. 2,152,138

' HEAT TREATING EQUIPMENT Filed April 20, 1937 v 5 sheets-sheet 4 INVENTORS James F/e fcher Earl E. Schoessow' E ATTORNEY.

.vlarch 28, 1939.

.1. FLETCHER ET AL 2,152,138

HEAT TREATING EQUIPMENT Filed April 20, 1937 5 SheetsSheet 5 INVENTORS James F/efc/ier w! E. j choesson I I ATTORNEY.

Patented Mar. 28, 1939 j I V'VVUNITED STATES PATENT OFPlCE HEAT TREATING EQUIPMENT 1 James Fletcher, Akron, and Earl E. Schoessow, Barberton, Ohio, assignors to The Babcock & Wilcox-Company, Newark, N. J., a corporation of New Jersey Application April 20, 1937, Serial No. 137,934

12 Claims. (Cl. 263 -49) This invention relates to improvements in detransverse frame members atnthe end of the vices used in metal treating. It is more particuframework. larly concerned with improved annealing hoods Fig. 3 is a vertical section througha portion or boxes adapted for advantageous use in the of the annealing box near its top, showing the 6 annealing of steel sheets of considerable width relation of the shell to the framework'along the and length. edges of the roof and at the liftinglugsp- 1 In annealing operations such as are carried on Fig. 4 is a view in the nature of :asideelevain the steel sheet and plate industry, it 'is the tion of a part of the structure shown in Fig. 3. usual practice to stack the sheetsupon a furnace Fig. 5 is a view in the nature of a horizontal floor and then place a heavy cast metal cover. section through acorner of the shell anda corner over the stack of sheets. Thelower edges of the of'the interior framework, taken on the line 55 cover rest upon the. flat bottom of the furnace or of Fig. '6. the bottom of an annealing base. Appropriate Fig. 6 is a view in. the nature of a partial side sealing material, such as sand, is placed against elevation showing the relationship of the shell the meeting parts of the cover or shell, and the to the frame members at a bottom corner of the 15 furnace floor or the bottom of the box, to prevent box. oxidation of the sheets or other materials which Fig. 7 is a partial plan showing the relationship are to be annealed. It is important, during such ,of the alloy sealing pads to the liftinglugs. annealing operations that the materials treated Fig. 8 is a partial vertical section of a part of be prevented from oxidation effects to a maxianother embodiment of the invention. 20

mum degree. Fig. 9 is a partial vertical section, on an en- Such cast metal covers as have been used in larged scale, of the embodiment indicated .in

- these operations have been of excessive size and I Figs. 8, 10, and 11. This viewis taken on line weight, some of them weighing as much as 30,000 99 of Fig. 10 0f the drawings.

pounds. They are expensive to manufacture and .Fig. 10 is a plan showing a part of the roof-of 25 diflicult to handle. In the annealing operations the shell of the Fig. 8 embodiment broken away. they become coatedwith scale which increases Fig. 11 is a view in the nature of a vertical secin thickness as the cover or shell is continued in tion taken on a P ane at right angles o the Plane use. This increases the resistance of the anof Fig. 8.

nealing cover or shell to the transfer of heat and, Fig. 12 is a view in the nature of'an isometricconsequently, lengthens the time for the annealdrawing showing the relation of the lifting :lugs ing operation. It is an object of this invention to the main" beam and the connector secured to to overcome these difficulties. the lugs and the beam. r 4

One object of the inventionis to provide an 'Fi 13 is a p ia plan of the embodiment annealing box which will have an exceedingly low including the structure indicated in Fig; 12. 35 weight because of the provision of a shell of thin Fig. 14 is a partial vertical section taken on sheet metal which has the property of being a plane indicated by theline |4--l4 of Fig. 13. highly resistant to heat. It is a purpose of this Fig. 15 is a partial vertical section taken on invention to so support such a shell that it will a plane indicated by the section line l5|5 of not warp excessively out of shape, but is free to Fig. 14.

expand and contract within necessary limits. Fig. 16 is a detailed view in the nature of an Other objects of the invention will appear as isometric view showing how the shell may be the Eccompanying description proceeds. tied to the uprights and horizontals of the frame For the purpose of illustrating the invention, at various positions while still permitting the reference willbe made in the following descripshell to move freely relative to the components 45 I tion to preferred embodiments which are shown of the framework. 7

in the accompanying drawings. Fig. 17 is an isometric view indicating a manner In the drawings: in which a modified form of the annealing equip- Fig. 1 is a view in the nature of a perspective ment may be made. Y

a part of the shell broken away to show the shella metal framework III of relatively light weight, supporting framework. and a sheet metal shell, l2. The latter constitutes Fig. 2 is a view in the nature of a diagrama substantially integral cover enclosing the sides, matic view; taken on the small scale and showing ends, and top of the framework. For the purpose 55 the transverse arches, as well as the upright and of efiecting high rates of heat transfer and for 55 0 view showing'the illustrative annealing box with The illustrative annealing apparatus includes the purpose of preventing the oxidation of the metal undergoing heat treatment, the shell is preferably gas tight. Furthermore, and in the interest of economy of heat treating operations, the metal of the shell is very thin. The shell is not self-supporting. It requires the support of the framework to maintain it in the desired form during the use of the apparatus.

Preferably, the shell I2 is secured to the framework In only around the perimeter of the latter and at its base. Such securement is preferably effected by welding, and such securement is necessary in order that the annealing box may be capable of being transported into and out of its operative position, with facility. In the use of the illustrative equipment, metal sheets to .be heat treated are stacked on a furnace floor and an annealing box is lowered over the stack of sheets. Band or other sealing material is placed around the lower edges of the 'box, and the furnace enclosing the box is prepared for operation. Its burners are turned on and impinging flames contact the shell of the box. The thin shell begins to expand, and since it is in a large part free to move independently of the framework, little or no strain is set up in the framework by the expansion of the shell. The shell expands in all directions, thus leaving the frame to approach the annealing temperatures of the charge without appreciable restriction. As the framework comes up to annealing temperature, it takes up {the differential expansion and remains at annealing temperatures during the heating of the charge.

After the annealing operation has been carried on for sufficient length of time, the box is withdrawn from the furnace. Air at atmospheric temperatures immediately contacts with the shell, and inasmuch as the latter is relatively thin, little warpage results from the rapid cooling of the outer faceof the shell while the inner face of the shell remains at temperatures several hundred degrees higher. As the shell cools down it contracts more rapidly than the supporting framework. Hence, provision for the consequent relative movements of the shell and the framework must be made. To avoid high strains in the shell during this stage of theuse of the equipment, some portions of the shell are bent or bowed to provide suitable clearances at either end of the box, and preferably, along the junc- 'tures of the roof portion of the shell with its sides and ends. Such an upright bowed portion is shown at l4 in Fig. 5 at the juncture of the side wall l6 and the end wall 18. In Fig. 3 there is shown a horizontal bulge or bowed portion 20 at the junction of the roof portion 22 and the side wall i6. The structure of the framework fillets 24, adjacent the bowed portions 20 is also such as to add to the desired clearances. These fillets are recessed away from the bowed portions 20, as clearly indicated at 26. Along the junctures of the roof portion 22 with the end walls l8, the inclined inverted channels 30 are formed in the shell for similar clearance purposes.

The framework for the illustrative equipment includes a main beam 32 extending along the roof of the box. When the box is to be moved from one position to another, it is lifted by the attachment of some lifting means to lifting lugs indicated generally at 34. As shown, these lifting lugs consist of bars or plates 38 and 38 welded to the beam 32 on opposite sides thereof. They extend up through openings 40 in the shell and are preferably joined and enclosed at their upper ends by metal parts made of an alloy of high resisting properties. These parts include the cover 42, sleeve 44, and the corrugated pads 46. The latter are corrugated, and spaced from the roof of the shell parts 48 as shown in Fig. 3

preferably welded to the cross beams.

The roof of the box is supported by spaced uprights 60 and 62, and these uprights are maintained in their operative positions by base mem: bers 64 and 66 and struts 68, all of these parts being preferably united by welding.

Along the sides of the box the cross beams 52 are preferably joined to the uprights 60 and 62 by the recessed fillets 24. The latter are maintained in their operative positions by the struts Ill and I2.

As indicated in Fig. 4 of the drawings, the framework, and hence the entire box, is rigidified by constructing the fillets 24 of material which is somewhat thicker than the cross beams 54 and the uprights 80. Preferably, the ends of the fillets are tapered down to the thickness of the uprights and the cross beams for promoting effective welding of these parts together.

One important advantage of the illustrative annealing equipment over the heavy cast steel annealing boxes which have heretofore been used is that it takes a much shorter time to bring the illustrative box and its charge up to annealing temperature. The heating cycles of the annealing operation may, by the use of the illustrative equipment, be reduced as much as twentyfour hours. This also involves a material saving in the amount of fuel required in each annealing cycle. Also, because of the low weight of the illustrative equipment much less power is required to handle it, transporting it to and from its operative position.

The lifting lugs of the embodiment indicated in Figs. 12, 13, and 14 are arranged so as to slidably grip the upper flanges of the main beam 80. In this embodiment, the latter is, for lightness of construction, as well as for co-operation with the lifting lugs, in the form of an I-beam. The relation of the lifting lugs 82 and 84 to the beam is particularly wellshown in Fig. 12 of the drawings. The upper flange 86 of the beam 80 is received within opposed slots or grooves 88 and 90 of the lifting lugs. The latter may have their lower portions 92 and 94 bent back to form these grooves.

The connector 96 is positioned above the beam 80 and is parallel therewith, as shown. In Fig. 12 the connector is indicated as a bar rigidly connected at its ends to the lifting lugs 82 and 84. Intermediate its ends this bar is rigidly secured tothe flange 86 of the bar 80, and this may be accomplished through the intermediacy of the weld 98. This construction prevents excessive stresses during the moving of the annealing equipment to and from its operative position, and prevents disruption of the shell by these moving operations. It also maintains the proper positioning of the lugs 82 and 84, during all thermal conditions.

The embodiment illustrated Flgs'fit'ib; and

welded to the tubular connector. The purpose of using the latter is to provide a lightweight construction that will rapidly reach approximately the same temperature as the shell and still be rigid enough to maintain the correct position of the lifting lugs throughout the temperature range of the shell. This connector, of course, also prevents the lifting lugs from moving toward each other during the lifting operation, but this latter function also applies to the connector 96 of the Fig. 12 embodiment.

The lifting lug I02 of the Figs. 8-11, inclusive, embodiments is preferably of the same construc tion as the lugs 82 and 84 previously described,

but it is shown sheathed with the same lightweight alloy sheet metal which forms the shell II 0. This sheathing is indicated at H2 in Fig. 9. The lower part of each lug is shown as extending through an opening in the shell I I0. The latter is reinforced around these openings by a plate II4, preferably welded .to the shell around its perimeter at II6 andwelded to the lug and to the sheathing II2 as indicated at 8., This plate may be also welded to the tubular connector I00. The latter is shown as extending between spaced portions of the plate, in Fig. 8. This figure also illustrates thesections of the shell II as contacting with the connector I00, to which they are rigidly secured.

.Reverting to the embodiment illustrated in 12, 13, and 14, the bar 96, between the lugs 82 and 84, is preferably sheathed by a lightweight alloy metal of the same material as the shell I20. This sheathing is indicated at I22 in Fig. 15 of the drawings, and is preferably welded to the shell as indicated at I24. The lugs 82 and extend through openings in the shell I20 and the shell is reinforced around each lug by a plate I26 which preferably closely flts against the lug. This plate is welded along its outside perimeter to the shell I20 as indicated at I28, and around its inner perimeter it is welded to the contiguous lug as indicated at I30. Each plate preferably abuts against the opposite sides of the connector bar 96 and is welded thereto.

At various points on the illustrative structure the shell may be tied to the elements of the framework by clips I32. These are well indicated in Fig. 16 of the drawings where they are shown looped around a frame member I34 and having angularly bent .bases I36 and I38. The latter are preferably secured to the shell I20 by welding and it is-within the scopeof the invention that the upper 'and lower parts I40 and I42 of each clip are spaced apart a-distance much greater than the thickness of the associated frame member I34. Thus, the portion of the shell I20 ad-' jacent the frame member I34 may move, within limits, in any direction relative to the framework member without imposing any stresses whatever in the shell. In spite of any such movements the shell may not move too far away from the framework. It cannot collapse or buckle, and it is generally maintained in its operative position, completely enclosing the framework. v

Fig. 17 of the drawings indicates a different manner of holding the shell in operative relation to the base rails of the framework. In this emguideway I52.

of the sub-joined claims. I

of the revised statutes, we further clearly setforth bodiment' of the invention the shell I42 envelopes a framework similar to that shown in other'flgures of the-drawings, and the shell is of similar construction as to the kind and gauge. of the metal employed. The shell, however, is not diguideway. The'guide bar I46 is preferably joined with the base rail'by the weld I56.

When the shell I 42 is subjected to a'temperature variation different from that of the supporting framework, the flange I54 of the shell may freely move upwardly or downwardly with respect to the base rail I44, but the construction is such that. this flange always remains in the The shell is thus maintained in operative relation to the base rails of the framework at all times.

When the Fig. 17 construction is employed, the uprights of the framework may be readily united with the base rails so as to form a strong and rigid framework. Fig. 17 shows one of the-uprights I58as having its lower'end reduced in width, and tightly received within the channel of the base rail I44. This reduced lower end ispref erably weldedto the base-rail on both sides of the upright or vertical bar I58. A part of oneof such welds is indicated at I60.

While the invention has been described with Having described our invention in the manner prescribed by law, and particularly section 4888 the invention in the following claims.

We claim: 1

, 1. An annealing box comprising; in combination; a shell supporting framework includingbase rails, a series of inverted U-shaped frame members including cross beams and uprights spaced longitudinally of and connected. to the base rails, and a'- main top beam connecting said cross beams; and an inverted U-shaped thin metal shell having its lower edges welded to the base rails and its top portion secured by welding to the main beam and its portions intermediate the base rails and main beam being unsecured to the framework so as to permitsubstantially free expansion of the shell relative to the frame.

.its portions intermediate the base rails and the .main beam being unsecured to the framework so as to permit substantially free expansion of the shell relative to the framework, said framework being provided with lifting lugs'rigidly secured thereto and extending through openings in the with the'scope.

bination, a lightweight metallic framework in-.

shell,"and flexible means uniting the lugs and the shell so as to permit movement of the shell with reference to the lugs while maintaining a gastight encasement.

3. Annealing equipment of the type shown, comprising, in combination, a lightweight metallic framework including a main beam, a thin sheet metal shell enclosing the framework, means for holding the shell in operative position relative to the framework without imposing any excessive strains due to the different operative thermal ranges of the framework and the shell, lifting lugs slidably engaging the main beam, a metallic connector parallel with the main beam and rigidly connected at its ends with the lifting lugs, means for rigidly securing the connector to the main beam at a position between the lifting lugs, and means for uniting the shell with the lifting lugs in gas-tight relationship.

4. Annealing equipment of the type shown,

comprising, in combination, a lightweight metallic framework including a main beam, a thin sheet metal shell enclosing the framework, means for holding the shell in operative position'relative to the framework without imposing any excessive strains due to the different operative thermal ranges of the framework and the shell, lifting lugs slidably engaging the main beam, a tubular metallic connector parallel with the main beam and rigidly connected at its ends with the lifting lugs, means for rigidly securing the connector to the main beam ata position between the lifting lugs, and means for uniting the shell with the lifting lugs in gas-tight relation.

5. Annealing apparatus, comprising, in comcluding a main beam, a thin sheet metal shell enclosing the framework in a telescoping relationship, means for holding the shell in operative position relative to the framework without imposing any excessive strains due to the different operative thermal ranges of the framework and the shell, lifting lugs slidably engaging the main beam, a metallic bar parallel with the main beam and rigidly connected at its end with the lifting lugs, means for rigidly securing the bar to the main beam at a position between the lifting lugs, and .means for uniting the shell with the lifting lugs in gas-tight relationship.

6. In a metallic structure, a-lightweight metallic framework, a lightweight metallic gas-tight shell constructed of thin sheet metal and telescoped over the framework so as to enclose it, lifting means for transmitting lifting forces from positions exterior of the shell directly to the framework without imposing excessive stresses on the shell, means for holding the shell in its enclosing position while permitting it to be subjected to.difierent temperature ranges, and flexible closure means completing a gas-tight seal around the lifting means while permitting the shell to move relative to the lifting means under the influence of temperature changes.

7. Annealing apparatus, comprising, in combination, a lightweight metallic framework includinga main beam, a thin sheet metal shell enclosing the framework, clips embracing the framework members for holding the shell in operative condition relative to the framework without imposing any excessive strains due to the different operative thermal ranges of the framework and the shell, lifting lugs, and means for uniting the shells with the lifting lugs in gas-tight condition.

8. In annealing apparatus, a lightweight metallic framework including a main beam and channeled base-rails, a thin sheet metal shell enclosing the framework in telescoping relationship, and means for holding the shell in operative position relative to the framework without imposing any excessive strains, due to the differ ent operative thermal ranges of the framework and the shell, said -means including guide bars welded to the base rails and having portions spaced therefrom to form a guideway circumscribing the framework and receiving an upturned portion of the lower edge of the shell in such a manner that there may be relative motion of this upturned edge with respect to the base rails andthe guide bars.

9. In annealing apparatus, a lightweight metallic framework including a main beam and channeled base rails, a thin sheet metal shell enclosing the framework in telescoping relationship, and means for holding the shell in operative position relative to the framework without imposing any excessive strains due to the different operative thermal ranges of the framework and the shell, said means including a guideway circumscribing the framework and receiving a flange in such a manner that there may be relative motion of the shell with respect to the base rails.

10. In annealing apparatus, a lightweight metallic framework including a main beam, and

channeled base rails, a thin sheet metal shell en-' closing the framework in telescoping relationship, and means for holding the shell in operative position relative to the framework without imposing any excessive strains due to the different operative thermal ranges of the framework and the shell, said means including a guideway circumscribing the framework and receiving an upturned portion of the lower edge of the shell .in such a manner that there may be relative motion of this upturned edge with respect to the base rails and theguide bars.

11. Annealing equipment of the type shown,

comprising, in combination, a lightweight metallic framework including a main beam, a thin sheet metal shell enclosing the framework, framework engaging clips for holding the shell in operative condition relative to the framework without imposing any excessive strains due to the different operative thermal ranges of the framework and the shell, lifting lugs slidably engaging the main beam, a metallic connector parallel with the main beam and rigidly connected at its ends with the lifting lugs, means for rigidly securing the connector to the main beam at a position mid-way of the lifting lugs, and means for uniting the shell with the lifting lugs in gas-tight condition.

12,. Heat treating equipment comprising a metallic'framework including upright side members and connecting roof members, a lightweight rolled metal shell constituting a unitary gastight enclosure for the framework, said shell including a channelledportion, and means around the framework and co-operating with the channelled portion to hold the shell in operative relation thereto without imposing excessive strains due to the different operative thermal ranges of the framework and the shell, said means including a peripheral element received in the channelled portion in such a manner that there may be relative sliding motion between said shell and the frame.

JAMES FLETCHER.

EARL E. SCHOESSOW. 

